/* let arr =[1,2,{n:3}]
let arr2 = [3,4]
let newArr = [].concat(arr)
arr[2].n=30
console.log(newArr); */
let arr =[1,2,{n:3}]
let arr2 = [3,4]
let newArr = [...arr]
arr[2].n=30
console.log(newArr);
